1. Field of the Invention
The present invention relates to a surface mounting apparatus, and more particularly to a surface mounting apparatus and a surface mounting method capable of holding a plurality of components at a time by head units coupled to a plurality of Y-frames and then mounting the same on a printed circuit board.
2. Description of the Conventional Art
A conventional surface mounting apparatus is structured to recognize the patterns of the electronic components by the image processing to determine the positioning of the components and then to mount the components at the positions determined on a printed circuit board (PCB).
As the above-described apparatus, there is known a surface mounting apparatus as shown in FIG. 1. As shown in FIG. 1, the surface mounting apparatus 1 consists of an XY frame 2, a head unit 3 supported to be moved in the X and Y directions by the XY frame 2, a component feeder 4 for supplying the electronic components 8, a position determining unit 5, and a conveyer 7 carrying the PCB 6. Further, the XY frame 2 consists of an X frame 2b and Y frames 2a. 
In case the electronic components 8 are mounted on the PCB 6 being carried by the conveyer 7, the operation of the surface mounting apparatus thus constructed is as follows. Namely, when the XY frame 2 is driven by a driving means (not shown), the head unit 3 is moved to a position on a predetermined piece of electronic component 8 placed on the component feeder 4. A suction means connected to a suction nozzle 3a of the head unit 3 is then operated, so that the suction nozzle 3a vacuum sucks the electronic component 8 to hold it. The suction nozzle 3a is adapted to hold and support the electronic component 8 in the mounting direction of the component 8 on the PCB 6.
The XY frame 2 is driven by a driving means (not shown) to be moved to a position on the position determining unit 5. There are disposed the electronic components 8 within a view field of an image capturing means at the mounting direction described above.
The head unit 3 is moved to a position determined by the position determining unit 5 over the PCB 6 which is transferred to the mounting position by the conveyer 7. Thus, the electronic component 8 held by the suction nozzle 3a of the head unit 3 is mounted on the PCB 6. It is noted that the suction nozzle 3a of the head unit 3 releases the vacuum sucked electronic component 8 when the suction means becomes inactivated. By such an operation, a piece of electronic component 8 can be mounted on the PCB 6.
In order for the electronic component sucked by the nozzle to be placed on the PCB, although a plurality of suction nozzles installed at the XY frame are provided, the conventional surface mounting apparatus having the above-mentioned structure places individually one by one the sucked components on the PCB, through the movement of the XY frame.
In consequence, since the prior art performs the placing of the electronic components on the PCB one by one, the mounting speed is reduced, thus resulting in the reduction of productivity. In case of a large size of the XY frame, this type of XY frame cannot meet both the component mounting speed and the accuracy thereof.
Therefore, an object of the present invention is to provide a surface mounting apparatus and a surface mounting method, by which electronic components are accurately mounted on a printed circuit board adapted to be freely moved within a work area, by using a plurality of Y-frames each being formed in a stripe shape and which are movable in a predetermined direction.
Another object of the present invention is to provide a surface mounting apparatus and a surface mounting method which enables simultaneously picking up and placing a plurality of electronic components on a printed circuit board within respective work areas.
To accomplish the above objects according to the present invention, there is provided a surface mounting apparatus comprising: a pair of fixed frames; another frames which correspond to said pair, the number of said another frames including at least more than one compared with that of said fixed frames. Moreover, the surface mounting apparatus according to the present invention comprises: a moving member movable freely in a predetermined direction, and on which a printed circuit board is seated; a plurality of fixed X-frames; a plurality pairs of Y-frames installed with respect to the X-frames, each of Y-frames being formed in a stripe shape; head units installed at predetermined places of the Y-frames; and a plurality of vision units installed at predetermined places with a predetermined spacing between the X-frame and the vision unit.
According to another aspect of the present invention, there is also provided a method for surface mounting electronic components on PCB, the method comprising the steps of: providing the PCB from a conveyer to a moving member; moving the PCB to predetermined place; head units holding electronic components; identifying if the head units accurately hold the electronic components; holding the electronic components again, if the electronic components are not held accurately; mounting the electronic components on the PCB, if the electronic components are held accurately; confirming whether or not predefined movement routes are completed; and discharging the PCB, if the predefined movement routes are completed.
According to still another aspect of the present invention, there is provided a surface mounting apparatus comprising: at least one or more conveyers for carrying a PCB; a PCB distribution unit for distributing the PCB carried from the conveyers to predetermined places; a plurality of fixed X-frames; a plurality of Y-frame pairs installed with respect to the X-frames, each Y-frame being formed in a stripe shape; a head unit installed at predetermined place of the Y-frame; a PCB recovery unit for recovering the PCB; a plurality of vision units installed at predetermined places, spaced apart at a predetermined spacing therebetween; and at least one or more feeders for supplying the electronic components. The surface mounting method according to the present invention comprises the steps of: providing the PCB from a first conveyer to a moving member; transferring the PCB from the first conveyer to the second conveyer using a PCB distribution unit; respective head units holding respective electronic components from first and second component feeders; identifying if each of the head units accurately holds the electronic component; holding the electronic components again, if the electronic components are not held accurately; and mounting the electronic components on the PCB, if the electronic components are held accurately; moving the PCB by a determined distance; confirming if a predefined movement route has been completed; moving the PCB from the second conveyer to the first conveyer using a PCB recovery unit; discharging the PCB so that the PCB transferred from the second conveyer dose not interfere with another PCB transferred from the first conveyer.
According to the present invention, the surface mounting apparatus is advantageously provided in which a plurality of Y-frames each being formed in a strip shape, are provided to hold lots of components at a time, and after confirming them by the vision unit, the plural components are mounted on the PCB. The surface mounting of plural components at a time reduces overall operation time, thus resulting in an improvement of overall productivity. Further, an advantage is also provided in that difference between the productivity estimated at optimal conditions and the practical productivity can be significantly reduced.